Multi-layer high spin golf ball

ABSTRACT

A golf ball comprising a core of one or more layers, a cover layer of one or more layers and a mantle layer disposed between the core and the cover. The mantle layer comprises a thermoplastic material, preferably having a hardness of greater than 60 Shore D and a Bashore resilience of greater than 34 and a vicat point of greater than 350° F.

This application is a continuation of U.S. patent application Ser. No.10/008,013 filed Nov. 13, 2001, now U.S. Pat. No. 6,616,549, which is acontinuation-in-part of U.S. patent application Ser. No. 09/161,223, nowU.S. Pat. No. 6,315,680, filed Sep. 28, 1998, which is acontinuation-in-part of U.S. patent application Ser. No. 08/996,718, nowU.S. Pat. No. 6,124,389, Ser. No. 08/706,008 now U.S. Pat. No.5,813,923, Ser. No. 08/603,057 now U.S. Pat. No. 5,759,676, Ser. No.08/606,373 now U.S. Pat. No. 5,721,304, and Ser. No. 08/746,362 now U.S.Pat. No. 5,810,678, which were filed Dec. 23, 1997, Aug. 30, 1996, Feb.16, 1996, Feb. 23, 1996, and Nov. 8, 1996, respectively, which arecontinuation-in-part applications of patent application Ser. No.08/482,522, now U.S. Pat. No. 5,688,191, filed Jun. 7, 1995.

FIELD OF THE INVENTION

This invention relates generally to golf balls, and more specifically,to a multilayer golf ball. In particular, this invention relates to agolf ball having a core with one or more layers, at least one coverlayer with a flexural modulus ranging from about 1,000 psi to about200,000 psi and one or more mantle layers disposed between the core andcover layer. The multilayer golf balls of the present invention havebeen found to provide good distance and spin characteristics.

BACKGROUND OF THE INVENTION

Conventional golf balls can be divided into two general types or groups:two piece balls or wound balls (also know as three-piece balls). Thedifference in play characteristics resulting from these different typesof constructions can be quite significant.

Balls having a two piece construction are generally most popular withthe average recreational golfer because they provide a very durable ballwhile also providing maximum distance. Two piece balls are made with asingle solid core, usually made of a crosslinked rubber, which isencased by a cover material. Typically the solid core is made ofpolybutadiene which is chemically crosslinked with zinc diacrylateand/or similar crosslinking agents and is covered by a tough, cut-proofblended cover. The cover is generally a material such as SURLYN®, whichis a trademark for an ionomer resin produced by DuPont. The combinationof the core and cover materials provide a “hard” ball that is virtuallyindestructible by golfers. Further, such a combination imparts a highinitial velocity to the ball which results in improved distance. Becausethese materials are very rigid, two piece balls have a relatively lowspin rate which makes them difficult to control, particularly on shorterapproach shots. However, as golf ball manufacturers continue to improvethe spin and feel characteristics of the two piece ball, it is likelythat the two piece ball will continue to grow in popularity.

Consequently, a need exists for an improved ball which provides relativeease of manufacturing, durability and distance.

SUMMARY OF THE INVENTION

The present invention is directed towards a multi-layer golf ball whichprovides good spin characteristics, while also providing the distance,durability and relative ease of manufacturing.

The present invention is further directed towards a multi-layer golfball which comprises a core with one or more layers; at least one coverlayer; and one or more mantle layers disposed between the core and coverlayer, wherein the mantle layer comprises dynamically vulcanizedthermoplastic elastomer, functionalized styrene-butadiene elastomer,thermoplastic polyurethane, a thermoplastic polyetherester orpolyetheramide, a thermoplastic ionomer resin, a thermoplasticpolyester, another dynamically vulcanized elastomer, another afunctionalized styrene-butadiene elastomer, another a metallocenepolymer or blends thereof and/or thermoset materials.

In a preferred embodiment, the present invention is also directedtowards a multi-layer golf ball which comprises a core; a cover layercomprising an inner layer and an outer layer, wherein the outer layercomprises a material with a lower melting point or heat of reactiontemperature (also referred to as cure temperature) than that of thematerial of the inner layer; and at least one mantle layer disposedbetween the core and cover layer, wherein the mantle layer comprisesdynamically vulcanized thermoplastic elastomer, functionalizedstyrene-butadiene elastomer, thermoplastic polyurethane or metallocenepolymer and blends thereof.

The present invention is still further directed to a multi-layer golfball which comprises a core, at least one cover layer and at least onemantle layer disposed between the core and cover layer whereinproperties such as the thickness, hardness, flexural modulus, tensilemodulus or Bashore resilience of the various layers is such as toprovide a ball with optimum performance characteristics.

BRIEF DESTRIPTION OF THE FIGURES

FIG. 1 is a perspective view of a golf ball according to the presentinvention.

FIG. 2 is a cross-sectional view of a golf ball according to the presentinvention.

FIG. 3 is a cross-sectional view of a second golf ball according to thepresent invention.

FIG. 4 is a cross-sectional view of a third golf ball according to thepresent invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1 and 2, this invention is particularly directedtowards a multi-layer golf ball 10 which comprises a core 12, at leastone cover layer 16 and at least one mantle layer 14 disposedtherebetween, wherein the mantle layer comprises dynamically vulcanizedthermoplastic elastomer, functionalized styrene-butadiene elastomer,thermoplastic polyurethane or metallocene polymer or blends thereof. InFIG. 3, the invention is directed to a ball 20, comprised of a corehaving layers 12 a, 12 b and/or 12 c, mantle layer 14 and cover 16. InFIG. 4, the present invention is directed to a golf ball 30 comprised ofa core having layers 12 a, 12 b and/or 12 c, mantle layer 14 and coverlayers 16 a and 16 b. These aspects of the invention are discussed inmore detail below.

Suitable dynamically vulcanized thermoplastic elastomers includeSantoprene®, Sarlink®, Vyram®, Dytron® and Vistaflex®. Santoprene® isthe trademark for a dynamically vulcanized PP/EPDM. Santoprene® 203-40is an example of a preferred Santoprene® and is commercially availablefrom Advanced Elastomer Systems. Examples of suitable functionalizedstyrene-butadiene elastomers include Kraton FG-1901x and FG-1921x, whichis available from the Shell Corporation. Examples of suitablethermoplastic polyurethanes include Estane® 58133, Estane® 58134 andEstane® 58144, which are commercially available from the B. F. GoodrichCompany. Suitable metallocene polymers whose melting points are higherthan the cover materials can also be employed in the mantle layer of thepresent invention. Further, the materials for the mantle layer describedabove may be in the form of a foamed polymeric material. For example,suitable metallocene polymers include foams of thermoplastic elastomersbased on metallocene single-site catalyst-based foams. Suchmetallocene-based foam resins are commercially available from SentinelProducts of Hyannis, Mass.

The mantle layer may comprise up to 100% by weight of a dynamicallyvulcanized thermoplastic elastomer, a functionalized styrene-butadieneelastomer, a thermoplastic polyurethane, a metallocene polymer or blendsthereof. In a preferred embodiment of the present invention, the mantlelayer comprises Santoprene®, thermoplastic polyurethane or blendsthereof.

However, in another preferred embodiment of the present invention, themantle layer comprises a dynamically vulcanized thermoplastic elastomer,a functionalized styrene-butadiene elastomer, a thermoplasticpolyurethane or a metallocene polymer, a thermoplastic polyurethane, athermoplastic polyetherester or polyetheramide, a thermoplastic ionomerresin, a thermoplastic polyester, another dynamically vulcanizedelastomer, another a functionalized styrene-butadiene elastomer, anothera metallocene polymer or blends thereof.

Suitable thermoplastic polyetheresters include Hytrel® 3078, Hytrel®3548, Hytrel® 4078, Hytrel® 4069, Hytrel® 6356, Hytrel® 7246, andHytrel® 8238 which are commercially available from DuPont. Suitablethermoplastic polyetheramides include Pebax® 2533, Pebax® 3533, Pebax®4033, Pebax® 5533, Pebax® 6333, and Pebax® 7033 which are available fromElf-Atochem. Suitable thermoplastic ionomer resins include any number ofolefinic based ionomers including SURLYN® and Iotek®, which arecommercially available from DuPont and Exxon, respectively. The flexuralmoduli for these ionomers is about 1000 psi to about 200,000 psi.Suitable thermoplastic polyesters include polybutylene terephthalate.Likewise, the dynamically vulcanized thermoplastic elastomers,functionalized styrene-butadiene elastomers, thermoplastic polyurethaneor metallocene polymers identified above are also useful as the secondthermoplastic in such blends. Further, the materials of the secondthermoplastic described above may be in the form of a foamed polymericmaterial.

Such thermoplastic blends comprise about 1% to about 99% by weight of afirst thermoplastic and about 99% to about 1% by weight of a secondthermoplastic. Preferably the thermoplastic blend comprises about 5% toabout 95% by weight of a first thermoplastic and about 5% to about 95%by weight of a second thermoplastic. In a preferred embodiment of thepresent invention, the first thermoplastic material of the blend is athermoplastic polyetherester, such as Hytrel®.

The present invention also contemplates the use of a variety ofnon-conventional cover materials. In particular, the covers of thepresent invention may comprise thermoplastic or engineering plasticssuch as ethylene or propylene based homopolymers and copolymersincluding functional monomers such as acrylic and methacrylic acid andfully or partially neutralized ionomers and their blends, methylacrylate, methyl methacrylate homopolymers and copolymers, imidized,amino group containing polymers, polycarbonate, reinforced polyamides,polyphenylene oxide, high impact polystyrene, polyether ketone,polysulfone, poly(phenylene sulfide), reinforced engineering plastics,acrylonitrile-butadiene, acrylic-styrene-acrylonitrile, poly(ethyleneterephthalate), poly(butylene terephthalate), poly(ethylene-vinylalcohol), poly(tetrafluoroethylene) and their copolymers includingfunctional comonomers and blends thereof. These polymers or copolymerscan be further reinforced by blending with a wide range of fillers andglass fibers or spheres or wood pulp.

The core of the present invention may comprise a variety of materials,including those conventionally employed as golf ball cores. Theconventional materials for such cores include core compositions having abase rubber, a crosslinking agent, a filler and a co-crosslinking agent.The base rubber typically includes natural or synthetic rubbers. Apreferred base rubber is 1,4-polybutadiene having a cis-structure of atleast 40%. Natural rubber, polyisoprene rubber and/or styrene-butadienerubber may be optionally added to the 1,4-polybutadiene. The initiatorincluded in the core composition can be any known polymerizationinitiator which decomposes during the cure cycle. The crosslinking agentincludes a metal salt of an unsaturated fatty acid such as a zinc saltor a magnesium salt of an unsaturated fatty acid having 3 to 8 carbonatoms such as acrylic or methacrylic acid. The filler typically includesmaterials such as tungsten, zinc oxide, barium sulfate, silica, calciumcarbonate, zinc carbonate and the like.

In one embodiment of the present invention, the core comprises a centerwhich is liquid-filled or solid around which an elastic thread is wound.The solid center is typically a homogenous mass of a resilient materialsuch as polybutadiene or a natural rubber. The liquid-filled center istypically a thin walled sphere into which a liquid such as corn syrup isinjected by means of a hypodermic needle. The sphere is then sealed andfrozen to make the center a solid mass. The windings for either type ofcenter are provided by an elastic thread which is stretched and woundabout the center to a desired thickness.

In a second embodiment of the present invention, the core is solid andhas a diameter of at least about 1.50 inches. Preferably, the core hasone or more layers and one of the layers comprises a polybutadienerubber composition comprising a halogenated organosulfur compound. Thecover has a thickness of less than about 0.1 inches and preferablycomprises a polyurethane composition. The core can include a center andan outer core layer and the core preferably has a diameter of at leastabout 1.55 inches. The center can comprise the organosulfur compound toreduce the overall core and ball compression as set forth below. Suchcores are disclosed in co-pending U.S. application Ser. No. 09/951,963,which is incorporated by reference herein in its entirety.

The polybutadiene rubber composition preferably includes between about2.2 parts and about 5 parts of a halogenated organosulfur compound. Thehalogenated organosulfur compound may include pentafluorothiophenol;2-fluorothiophenol; 3-fluorothiophenol; 4-fluorothiophenol;2,3-fluorothiophenol; 2,4-fluorothiophenol; 3,4-fluorothiophenol;3,5-fluorothiophenol 2,3,4-fluorothiophenol; 3,4,5-fluorothiophenol;2,3,4,5-tetrafluorothiophenol; 2,3,5,6-tetrafluorothiophenol;4-chlorotetrafluorothiophenol; pentachlorothiophenol;2-chlorothiophenol; 3-chlorothiophenol; 4-chlorothiophenol;2,3-chlorothiophenol; 2,4-chlorothiophenol; 3,4-chlorothiophenol;3,5-chlorothiophenol; 2,3,4-chlorothiophenol; 3,4,5-chlorothiophenol;2,3,4,5-tetrachlorothiophenol; 2,3,5,6-tetrachlorothiophenol;pentabromothiophenol; 2-bromothiophenol; 3-bromothiophenol;4-bromothiophenol; 2,3-bromothiophenol; 2,4-bromothiophenol;3,4-bromothiophenol; 3,5-bromothiophenol; 2,3,4-bromothiophenol;3,4,5-bromothiophenol; 2,3,4,5-tetrabromothiophenol;2,3,5,6-tetrabromothiophenol; pentaiodothiophenol; 2-iodothiophenol;3-iodothiophenol; 4-iodothiophenol; 2,3-iodothiophenol;2,4-iodothiophenol; 3,4-iodothiophenol; 3,5-iodothiophenol;2,3,4-iodothiophenol; 3,4,5-iodothiophenol; 2,3,4,5-tetraiodothiophenol;2,3,5,6-tetraiodothiophenoland; and their zinc salts, the metal saltsthereof, and mixtures thereof, but is preferably pentachlorothiophenolor the metal salt thereof. The metal salt may be zinc, calcium,potassium, magnesium, sodium, and lithium, but is preferably zinc.

In one embodiment, the core has a compression less than about 75 and thegolf ball has a coefficient of restitution of greater than about 0.800.In another, the core has a compression less than about 75 and the golfball has a coefficient of restitution of greater than about 0.805. Instill another, the core has a compression less than about 55 and thegolf ball has a coefficient of restitution of greater than about 0.800.

The cover layer of the present invention comprises at least one layer ofa thermoplastic or thermosetting material. Any number of a wide varietyof cover materials maybe be used in the present invention. Among thepreferred conventional cover materials are ionomer resins obtained byproviding a cross metallic bond to polymers of monoolefin with at leastone member selected from the group consisting of unsaturated mono- ordi-carboxylic acids having 3 to 12 carbon atoms and esters thereof (thepolymer contains 1 to 50% by weight of the unsaturated mono- ordi-carboxylic acid and/or ester thereof). More particularly, suchacid-containing ethylene copolymer ionomer component of the subjectinvention includes E/X/Y copolymers where E is ethylene, X is asoftening comonomer such as acrylate or methacrylate present in 0-50(preferably 0-25, most preferably 0-2), weight percent of the polymer,and Y is acrylic or methacrylic acid present in 5-35 (preferably 8-35,most preferably 8-30) weight percent of the polymer, wherein the acidmoiety is neutralized 1-100% (preferably at least 40%, most preferablyat least about 80%) to form an ionomer by a cation such as lithium*,sodium*, potassium, magnesium*, calcium, barium, lead, tin, zinc* oraluminum (*=preferred), or a combination of such cations. Specificacid-containing ethylene copolymers include ethylene/acrylic acid,ethylene/methacrylic acid, ethylene/acrylic acid/n-butyl acrylate,ethylene/methacrylic acid/n-butyl acrylate, ethylene/methacrylicacid/iso-butyl acrylate, ethylene/acrylic acid/iso-butyl acrylate,ethylene/methacrylic acid/n-butyl methacrylate, ethylene/acrylicacid/methyl methacrylate, ethylene/acrylic acid/methyl acrylate,ethylene/methacrylic acid/methyl acrylate, ethylene/methacrylicacid/methyl methacrylate, and ethylene/acrylic acid/n-butylmethacrylate. Preferred acid-containing ethylene copolymers includeethylene/methacrylic acid, ethylene/acrylic acid, ethylene/methacrylicacid/n-butyl acrylate, ethylene/acrylic acid/n-butyl acrylate,ethylene/methacrylic acid/methyl acrylate and ethylene/acrylicacid/methyl acrylate copolymers. The most preferred acid-containingethylene copolymers are ethylene/methacrylic acid, ethylene/acrylicacid, ethylene/(meth) acrylic acid/n-butyl acrylate,ethylene/(meth)acrylic acid/ethyl acrylate, and ethylene/(meth) acrylicacid/methyl acrylate copolymers. The manner in which the ionomers aremade is well known in the art as described in e.g. U.S. Pat. No.3,262,272. Such ionomer resins are commercially available from DuPontCo. under the tradename SURLYN®. Likewise, other conventional materialssuch as balata, elastomer and polyethylene may also be used in the coverlayers of the present invention. Additionally, foamed polymericmaterials are suitable for use in the cover layers of the presentinvention. In particular, metallocene-based foam resins are useful inthe cover layers of the present invention.

In a preferred embodiment of the present invention, the cover layercomprises an inner layer and an outer layer. The inner layer of thecover is either a thermoplastic material such as a thermoplasticelastomer or a thermoplastic rubber.

Some examples of materials suitable for use as the outer cover layerinclude polyether or polyester thermoplastic urethanes as well asthermoset polyurethanes. A preferable thermoplastic material is athermoplastic urethane with a melting point of about 178° to about 205°C. A preferable thermoset material is a elastomer based, castableurethane. Suitable materials for the outer layer include Urethanes,ionomers with a low modulus and other durable materials such as EPDM andbutyl rubber. If the outer cover layer includes polyurethane, itincludes a prepolymer formed of a polyisocyanate and a polyol, and acuring agent. Preferably, at least one of the prepolymer and curingagent are saturated. In an alternative embodiment, the polyurethanecomposition comprises at least one of a UV absorber, a hindered aminelight stabilizer, or an optical brightener. Additionally, the presentinvention also contemplates the use of a polymeric foam material, suchas the metallocene-based foamed resin described above, as the materialfor either the outer cover layer or the inner cover layer, butpreferably not both layers.

In one embodiment of the present invention, it is preferable that thethermoplastic or thermosetting materials of the outer layer have amelting point or heat of reaction (cure) temperature less than themelting point or heat of reaction (cure) temperature of the materials ofthe inner layer or mantle layer.

The inner and outer cover layers of this embodiment of the invention canbe molded about the core and mantle layers through a variety ofconventional molding methods. For example, the cover layers can becompression molded, retractable pin injection molded, fixed pininjection molded, reaction-injection molded, cast around the core andmantle or a combination thereof. However, it is important that thematerials of the outer layer are characterized in that they have thermalproperties such that no flow of the inner layer or mantle layer materialoccurs during the molding of the outer cover layer regardless of theprocess employed to mold the layers.

The inner cover layer of this embodiment of the present invention has athickness of about 0.005 inches to about 0.060 inches. The outer coverlayer has a thickness of about 0.010 inches to about 0.100 inches. Inone embodiment, preferably, the inner cover layer has a thickness ofabout 0.010 inches to about 0.050 inches and the outer cover layer has athickness of about 0.030 inches to about 0.090 inches. In anotherembodiment, the outer cover layer is thinner than the inner cover layerand softer than the inner cover layer and has a thickness of between0.005 and 0.035.

The properties such as hardness, Bashore resilience, modulus, corediameter and mantle layer thickness of the golf balls of the presentinvention have been found to effect play characteristics such as spin,initial velocity and feel of the present golf balls.

In particular, the thickness of the mantle layer of the presentinvention is about 0.02 inches to about 0.125 inches. Preferably, thethickness of the mantle layer is about 0.02 inches to about 0.10 inches.Most preferably, the thickness of the mantle layer is about 0.03 inchesto about 0.05 inches. Similarly, the diameter of the core of the presentinvention is about 1.25 inches to about 1.60 inches, more preferablybetween about 1.30 inches and about 1.57 inches. Most preferably thediameter of the core is about 1.50 inches to about 1.58 inches. Theoverall diameter of the core and mantle layer is about 84% to about 97%of the overall diameter of the finished ball. The present multi-layergolf ball can have an overall diameter of any size. Although the UnitedStates Golf Association (USGA) specifications limit the minimum size ofa competition golf ball to more than 1.680 inches in diameter, there isno specification as to the maximum diameter. Moreover, golf balls of anysize can be used for recreational play. The preferred diameter of thepresent golf balls is from about 1.680 inches to about 1.800 inches. Themore preferred diameter is from about 1.680 inches to about 1.760inches. The most preferred diameter is about 1.680 inches to about 1.740inches. However, oversized game balls well in excess of 1.800 inches arealso contemplated by the present invention.

Several physical properties such as hardness, resilience and modulus ofthe various layers of the golf balls of the present invention arebelieved to impact the playing characteristics of such golf balls.Accordingly, it is preferable that the golf balls of one embodiment ofthe present invention have a mantle layer with a flexural modulus ofabout 500 psi to about 15,000 psi. Likewise, it is preferred that themantle layer have a tensile modulus of about 500 psi to about 15,000psi. In another embodiment having a cover layer with a flexual modulusof less than 20,000 psi, the mantle layer has a flexural modulus ofgreater than 45,000 psi.

Further, the core of the present invention has a Bashore resilience ofabout 30 to about 80. The mantle layer of the present invention has aBashore resilience of about 35 to about 80. Preferably the mantle layerhas a Bashore resilience of about 40 to about 80.

The golf balls of one embodiment to the present invention have a mantlelayer with a Shore D hardness of less than about 60 to provide low spin.Preferably, the Shore D hardness of the mantle layer is about 20 toabout 60. The core has a Shore D hardness of about 30 to about 65.Preferably, the core has a Shore D hardness of about 35 to about 60.

In another preferred embodiment, the mantle layer has a Shore D hardnessgreater than 60 and preferably comprises thermoplastic copolyetheresterblock copolymer, thermoplastic copolyesterester block copolymer,thermoplastic polyurethane, thermoset polyurethane, dynamicallyvulcanized thermoplastic elastormer, styrene-isoprene andstyrene-isoprene elastomer with a functional group such as maleicanhydride or sulfonic acid, polymer made using a metallocene catalyst,or blends thereof and/or thermoset materials.

The golf balls of the present invention can be made by any conventionalprocess employed in the golf ball art. For example, the solid cores canbe either injection or compression molded. Similarly, the undersizedwound cores of the present invention are produced through conventionalmeans. The mantle layer is subsequently injection or compression moldedabout the core. It is important that the mantle material be able tosustain the temperatures applied during the application of the coverlayer. As discussed below, the mantle preferably has a high vicat point.The cover layer or layers are then injection or compression molded orcast about the mantle layer.

Illustrated in Table I are a number of batch formulations for severalmantle layer compositions of the present invention, as well asproperties such a hardness (Shore D), Bashore resilience, flexuralmodulus, % strain at break and tensile modulus for each composition.

The following examples of batch compositions are given to illustrate thenovel multi-layer golf balls of the present invention. However, it is tobe understood that the examples are only for illustrative purposes andin no manner is the present invention limited to the specificdisclosures therein.

TABLE 1 Mantle Layer Compositions and Properties Hardness Flex ModulusTensile Modulus % Strain at Sample (Shore D) Resilience (psi) (psi)Break 1A   0% Estane 58091 28 54 1,720 756 563  100% Estane 58861 1B  25% Estane 58091 34 41 2,610 2,438 626   75% Estane 58861 1C   50%Estane 58091 44 31 10,360 10,824 339   50% Estane 58861 1D   75% Estane58091 61 34 43,030 69,918 149   25% Estane 58861 1E  100% Estane 5809178 46 147,240 211,288  10   0% Estane 58861 2A   0% Hytrel 5556 40 478,500 7,071 527  100% Hytrel 4078 2B   25% Hytrel 5556 43 51 10,0209,726 441   75% Hytrel 4078 2C   50% Hytrel 5556 45 47 12,280 10,741 399  50% Hytrel 4078 2D   75% Hytrel 5556 48 53 13,680 13,164 374   25%Hytrel 4078 3A   0% Hytrel 5556 30 62 3,240 2,078 810 no break  100%Hytrel 3078 3B   25% Hytrel 5556 37 59 8,170 5,122 685   75% Hytrel 30783C   50% Hytrel 5556 44 55 15,320 10,879 590   50% Hytrel 3078 3D   75%Hytrel 5556 53 50 19,870 16,612 580   25% Hytrel 3078 3E  100% Hytrel5556 58 50 24,840 17,531 575   0% Hytrel 3078 4A   0% Hytrel 4078 46 5111,150 8,061 597  100% Pebax 4033 4B   25% Hytrel 4078 46 53 10,6307,769 644   75% Pebax 4033 4C   50% Hytrel 4078 45 52 9,780 8,117 564  50% Pebax 4D   75% Hytrel 4078 42 53 9,310 7,996 660   25% Pebax 40334E  100% Hytrel 4078 40 51 9,250 6,383 531   0% Pebax 4033 5A   0%Hytrel 3078 77 50 156,070 182,869  9  100 Estane 5809 5B   25% Hytrel3078 65 48 87,680 96,543  33   75% Estane 5809 5C   50% Hytrel 3078 5249 53,940 48,941 102   50% Estane 5809 5D   75% Hytrel 3078 35 54 12,0406,071 852   25% Estane 5809 5E  100% Hytrel 3078 29 50 3,240 2,078 810no break   0% Estane 5809 6A  100% Kraton 1921 29 59 24,300 29,331 515  0% Estane 58091   0% Surlyn 7940 6B   50% Kraton 1921 57 49 56,580 —145   50% Estane 58091   0% Surlyn 7940 6C   50% Kraton 1921 56 5528,290 28,760 295   0% Estane 58091   50% Surlyn 7940 7A 33.3% Pebax4033 48 50 41,240 30,032 294 33.3% Estane 58094 33.3% Hytrel 3078 7B  30% Pebax 4033 48 50 30,650 14,220 566   40% Estane 58091   10% Hytrel3078 7C   20% Pebax 4033 41 54 24,020 16,630 512   40% Estane 58091  40% Hytrel 3078

Tables II and III provide test data for one embodiment of the presentinvention. In particular, the spin rate and velocity were measured for agolf ball of the present invention wherein the mantle layer was 100%Estane 58881 and Hytrel 4078, the cover was a conventional Li/Na SURLYN®blend and the core was a conventional cross-linked polybutadiene core.Also tested were conventional two piece golf balls (a Titleist HVC 90and Pinnacle Gold). Each ball was tested in a True Temper Test Machine.The test machine was configured to strike the balls with a Driver and anEight Iron.

TABLE II Spin Rate Test Results for Driver Spin Velocity Sample LaunchStd. (rpm) Std. (ft/sec) Std. Titleist HVC 9.3° 0.4 3038 287 159.8 1.6(Control) Pinnacle Gold 9.3° 0.4 3027 303 158.9 1.5 (Control) EstaneMantle w/ 8.8° 0.6 3677 188 156.50 0.9 1.30″ polybutadiene core andLi/Na SURLYN cover Hytrel Mantle w/1.30″ 8.7° 0.7 3479 259 155.9 2.0polybutadiene core and Li/Na SURLYN cover

TABLE III Spin Rate Test Results for 8-Iron Spin Velocity Sample LaunchStd. (rpm) Std. (ft/sec) Std. Titleist HVC 19.5° 0.3 7690 175 113.0 0.8(Control) Pinnacle Gold 19.8° 0.4 7549 209 112.5 1.0 (Control) EstaneMantle w/ 18.7° 0.5 8115 257 110.7 1.1 1.30″ polybutadiene core andLi/Na SURLYN cover Hytrel Mantle w/1.30″ 18.5° 0.4 7913 256 110.6 1.1polybutadiene core and Li/Na SURLYN cover

In another preferred embodiment of the present invention, the mantlelayer 14 is a thermoplastic copolyetherester block copolymer. Suitablethermoplastic copolyetheresters include Hytrel® 6356, Hytrel® 7246Hytrel® 8238 which are commercially available from DuPont. Hytrel® 6356being the most preferred.

Flex modulus (psi) Hardness Material (15% or less) (shore D) Vicat Point(F) Low acid ionomers 8940 51,000 65 145 7940 61,000 68 145 9910 48,00064 144 High acid ionomers 8140 75,000 65 136 Hytrel 6356 48,000 63 4127246 83,000 72 424 8238 174,000 82 433

The mantle layer according to the present invention preferably has aspecific gravity greater than about 1.2. In one embodiment, the specificgravity of the mantle layer is increased to about 1.25 by adding abut20% of a filler such as barium sulfate, zinc oxide, titanium dioxide andcombinations thereof. The most preferred golf ball is comprised of amantle layer make of Hytrel® 6356 and 20% zinc oxide or 10% Tungsten. Asshown above, the thermoplastic copolytheresters have a very high vicatsoftening temperature. This aids in manufacturing and particularly whena thermoset polyurethane cover is cast or reaction-injection-moldeddirectly over the mantle layer. Preferably, the mantle layer iscomprised of a material having a Vicat point greater than about 250° F.More preferably, the mantle layer material has a Vicat point greaterthan about 350° F.

Suitable dynamically vulcanized thermoplastic elastomers includeSantoprene®, Sarlink®, Vyram®, Dytron® and Vistaflex®. Santoprene® isthe trademark for a dynamically vulcanized PP/EPDM. Santoprene® 203-40is an example of a preferred Santoprene® and is commercially availablefrom Advanced Elastomer Systems. An example of suitable functionalizedstyrene-butadiene elastomer, i.e., styrene-butadiene elastomers withfuctional groups such as maleic anhydride or sulfonic acid, is KratonG7680 which is available from the Shell Corporation. Examples ofsuitable thermoplastic polyurethanes include Estane® 58861 and Estane®58091, which are commercially available from the B.F. Goodrich Company.Suitable metallocene polymers, i.e., polymers made with a metallocenecatalyst, whose melting points are higher than the cover materials canbe employed in the mantle layer of the present invention. Further, thematerials for the mantle layer described above may be in the form of afoamed polymeric material. For example, suitable metallocene polymersinclude foams of thermoplastic elastomers based on metalocene singlecatalyst-based foams. Such metallocene-based foam resins arecommercially available from Sentinel Products of Hyannis Massachusetts.

EXAMPLES

These and other aspects of the present invention may be more fullyunderstood with reference to the following non-limiting examples, whichare merely illustrative of the preferred embodiment of the presentinvention golf ball, and are not to be construed as limiting theinvention, the scope of which is defined by the appended claims.

The first example is a ball with a core diameter of about 1.45. The corehas a high specific gravity. Preferably, the core has a specific gravityof greater than 1.21 and most preferably about 1.23. The mantle layercovering the core has a thickness of about 0.05 to 0.1 inches,preferably about 0.06-0.08 inches. The mantle layer preferably has aspecific gravity of 0.91 and is made of Kraton G7890 or Hytrel 6356 or7246. The cover of the ball has a thickness of about 0.02 to 0.05 andmost preferably about 0.045 inches. The cover preferably has a specificgravity of about 0.95 to 1.1 and is made of SURLYN® or a MDI castpolyurethane as set forth below. The golf ball preferably weights about1.618 ounces.

The second example of a golf ball made according to the presentinvention has a core with a low specific gravity and a mantle layer witha high specific gravity. Preferably, mantle layer has a specific gravityof greater than 1.21, most preferably the mantle layer has a specificgravity of about 1.25. In the preferred embodiment, the mantle layer ismade of Hytrel 6356. The mantle layer has a thickness of about 0.02 toabout 0.05 inches, and most preferably about 0.03 inches. The cover ispreferably a cast polyurethane having a flexural modulus of less than20,000 psi.

The core of the second example preferably has a specific gravity of lessthan 1.21 and most preferably a specific gravity of about 1.13. Thediameter of the core is preferably 1.4 to 1.6 inches and most preferablyabout 1.55 inches. The cover layer surrounding both the core and mantlelayer has a thickness of about 0.02 to about 0.05 inches and mostpreferably about 0.03 inches. Further, the specific gravity of the coveris most preferably about 0.95 to about 1.1.

While the cover may be formed of any of the above-listed materials, theouter cover preferably includes a polyurethane, polyurea, or epoxycomposition, generally comprising the reaction product of at least onepolyisocyanate, polyol, and at least one curing agent. Anypolyisocyanate available to one of ordinary skill in the art is suitablefor use according to the invention. Exemplary polyisocyanates include,but are not limited to, 4,4′-diphenylmethane diisocyanate (“MDI”);polymeric MDI; carbodiimide-modified liquid MDI;4,4′-dicyclohexylmethane diisocyanate (“H₁₂MDI”); p-phenylenediisocyanate (“PPDI”); m-phenylene diisocyanate (“MPDI”); toluenediisocyanate (“TDI”); 3,3′-dimethyl-4,4′-biphenylene diisocyanate(“TODI”); isophoronediisocyanate (“IPDI”); hexamethylene diisocyanate(“HDI”); naphthalene diisocyanate (“NDI”); xylene diisocyanate (“XDI”);p-tetramethylxylene diisocyanate (“p-TMXDI”); m-tetramethylxylenediisocyanate (“m-TMXDI”); ethylene diisocyanate;propylene-1,2-diisocyanate; tetramethylene-1,4-diisocyanate; cyclohexyldiisocyanate; 1,6-hexamethylene-diisocyanate (“HDI”);dodecane-1,12-diisocyanate; cyclobutane-1,3-diisocyanate;cyclohexane-1,3-diisocyanate; cyclohexane-1,4-diisocyanate;1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane; methylcyclohexylene diisocyanate; triisocyanate of HDI; triisocyanate of2,4,4-trimethyl-1,6-hexane diisocyanate (“TMDI”); tetracenediisocyanate; napthalene diisocyanate; anthracene diisocyanate;isocyanurate of toluene diisocyanate; uretdione of hexamethylenediisocyanate; and mixtures thereof. Preferably, the polyisocyanateincludes MDI, PPDI, TDI, or a mixture thereof, and more preferably, thepolyisocyanate includes MDI. It should be understood that, as usedherein, the term “MDI” includes 4,4′-diphenylmethane diisocyanate,polymeric MDI, carbodiimide-modified liquid MDI, and mixtures thereofand, additionally, that the diisocyanate employed may be “low freemonomer,” understood by one of ordinary skill in the art to have lowerlevels of “free” monomer isocyanate groups, typically less than about0.1% free monomer groups. Examples of “low free monomer” diisocyanatesinclude, but are not limited to Low Free Monomer MDI, Low Free MonomerTDI, and Low Free Monomer PPDI.

The at least one polyisocyanate should have less than about 14%unreacted NCO groups. Preferably, the at least one polyisocyanate has nogreater than about 7.5% NCO, and more preferably, less than about 7.0%.

Any polyol available to one of ordinary skill in the art is suitable foruse according to the invention. Exemplary polyols include, but are notlimited to, polyether polyols, hydroxy-terminated polybutadiene(including partially/fully hydrogenated derivatives), polyester polyols,polycaprolactone polyols, and polycarbonate polyols. In one preferredembodiment, the polyol includes polyether polyol. Examples include, butare not limited to, polytetramethylene ether glycol (“PTMEG”),polyethylene propylene glycol, polyoxypropylene glycol, and mixturesthereof. The hydrocarbon chain can have saturated or unsaturated bondsand substituted or unsubstituted aromatic and cyclic groups. Preferably,the polyol of the present invention includes PTMEG.

Suitable polyester polyols include, but are not limited to, polyethyleneadipate glycol; polybutylene adipate glycol; polyethylene propyleneadipate glycol; o-phthalate-1,6-hexanediol; poly(hexamethylene adipate)glycol; and mixtures thereof. The hydrocarbon chain can have saturatedor unsaturated bonds, or substituted or unsubstituted aromatic andcyclic groups.

Suitable polycaprolactone polyols include, but are not limited to,1,6-hexanediol-initiated polycaprolactone, diethylene glycol initiatedpolycaprolactone, trimethylol propane initiated polycaprolactone,neopentyl glycol initiated polycaprolactone, 1,4-butanediol-initiatedpolycaprolactone, PTMEG-initiated polycaprolactone, and mixturesthereof. The hydrocarbon chain can have saturated or unsaturated bonds,or substituted or unsubstituted aromatic and cyclic groups.

Suitable polycarbonates include, but are not limited to, polyphthalatecarbonate and poly(hexamethylene carbonate) glycol. The hydrocarbonchain can have saturated or unsaturated bonds, or substituted orunsubstituted aromatic and cyclic groups.

Polyamine curatives are also suitable for use in polyurethane covers.Preferred polyamine curatives include, but are not limited to,3,5-dimethylthio-2,4-toluenediamine and isomers thereof;3,5-diethyltoluene-2,4-diamine and isomers thereof, such as3,5-diethyltoluene-2,6-diamine;4,4′-bis-(sec-butylamino)-diphenylmethane;1,4-bis-(sec-butylamino)-benzene, 4,4′-methylene-bis-(2-chloroaniline);4,4′-methylene-bis-(3-chloro-2,6-diethylaniline) (“MCDEA”);polytetramethyleneoxide-di-p-aminobenzoate; N,N′-dialkyldiamino diphenylmethane; p,p′-methylene dianiline (“MDA”); m-phenylenediamine (“MPDA”);4,4′-methylene-bis-(2-chloroaniline) (“MOCA”);4,4′-methylene-bis-(2,6-diethylaniline) (“MDEA”);4,4′-methylene-bis-(2,3-dichloroaniline) (“MDCA”);4,4′-diamino-3,3′-diethyl-5,5′-dimethyl diphenylmethane;2,2′,3,3′-tetrachloro diamino diphenylmethane; trimethylene glycoldi-p-aminobenzoate; and mixtures thereof. Preferably, the curing agentof the present invention includes 3,5-dimethylthio-2,4-toluenediamineand isomers thereof, such as Ethacure® 300, commercially available fromAlbermarle Corporation of Baton Rouge, La. Suitable polyamine curativesinclude both primary and secondary amines.

At least one of a diol, triol, tetraol, or hydroxy-terminated curativesmay be added to the aforementioned polyurethane composition. Suitablediol, triol, and tetraol groups include ethylene glycol; diethyleneglycol; polyethylene glycol; propylene glycol; polypropylene glycol;lower molecular weight polytetramethylene ether glycol;1,3-bis(2-hydroxyethoxy) benzene; 1,3-bis-[2-(2-hydroxyethoxy) ethoxy]benzene; 1,3-bis-{2-[2-(2-hydroxyethoxy) ethoxy] ethoxy} benzene;1,4-butanediol; 1,5-pentanediol; 1,6-hexanediol;resorcinol-di-(β-hydroxyethyl) ether; hydroquinone-di-(β-hydroxyethyl)ether; and mixtures thereof. Preferred hydroxy-terminated curativesinclude 1,3-bis(2-hydroxyethoxy) benzene; 1,3-bis-[2-(2-hydroxyethoxy)ethoxy] benzene; 1,3-bis-{2-[2-(2-hydroxyethoxy) ethoxy] ethoxy}benzene; 1,4-butanediol, and mixtures thereof.

Both the hydroxy-terminated and amine curatives can include one or moresaturated, unsaturated, aromatic, and cyclic groups. Additionally, thehydroxy-terminated and amine curatives can include one or more halogengroups. The polyurethane composition can be formed with a blend ormixture of curing agents. If desired, however, the polyurethanecomposition may be formed with a single curing agent.

In a particularly preferred embodiment of the present invention,saturated polyurethanes used to form cover layers, preferably the outercover layer, and may be selected from among both castable thermoset andthermoplastic polyurethanes. In this embodiment, the saturatedpolyurethanes are substantially free of aromatic groups or moieties.

Saturated diisocyanates which can be used include, but are not limitedto, ethylene diisocyanate; propylene-1,2-diisocyanate;tetramethylene-1,4-diisocyanate; 1,6-hexamethylene-diisocyanate (“HDI”);2,2,4-trimethylhexamethylene diisocyanate; 2,4,4-trimethylhexamethylenediisocyanate; dodecane-1,12-diisocyanate; dicyclohexylmethanediisocyanate; cyclobutane-1,3-diisocyanate;cyclohexane-1,3-diisocyanate; cyclohexane-1,4-diisocyanate;1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane; isophoronediisocyanate (“IPDI”); methyl cyclohexylene diisocyanate; triisocyanateof HDI; triisocyanate of 2,2,4-trimethyl-1,6-hexane diisocyanate(“TMDI”). The most preferred saturated diisocyanates are4,4′-dicyclohexylmethane diisocyanate (“HMDI”) and isophoronediisocyanate (“IPDI”).

Saturated polyols which are appropriate for use in this inventioninclude, but are not limited to, polyether polyols such aspolytetramethylene ether glycol and poly(oxypropylene) glycol. Suitablesaturated polyester polyols include polyethylene adipate glycol,polyethylene propylene adipate glycol, polybutylene adipate glycol,polycarbonate polyol and ethylene oxide-capped polyoxypropylene diols.Saturated polycaprolactone polyols which are useful in the inventioninclude diethylene glycol initiated polycaprolactone, 1,4-butanediolinitiated polycaprolactone, 1,6-hexanediol initiated polycaprolactone;trimethylol propane initiated polycaprolactone, neopentyl glycolinitiated polycaprolactone, PTMEG-initiated polycaprolactone. The mostpreferred saturated polyols are PTMEG and PTMEG-initiatedpolycaprolactone.

Suitable saturated curatives include 1,4-butanediol, ethylene glycol,diethylene glycol, polytetramethylene ether glycol, propylene glycol;trimethanolpropane; tetra-(2-hydroxypropyl)ethylenediamine; isomers andmixtures of isomers of cyclohexyldimethylol, isomers and mixtures ofisomers of cyclohexane bis(methylamine); triisopropanolamine, ethylenediamine, diethylene triamine, triethylene tetramine, tetraethylenepentamine, 4,4′-dicyclohexylmethane diamine,2,2,4-trimethyl-1,6-hexanediamine; 2,4,4-trimethyl-1,6-hexanediamine;diethyleneglycol di-(aminopropyl)ether;4,4′-bis-(sec-butylamino)-dicyclohexylmethane;1,2-bis-(sec-butylamino)cyclohexane;1,4-bis-(sec-butylamino)cyclohexane; isophorone diamine, hexamethylenediamine, propylene diamine, 1-methyl-2,4-cyclohexyl diamine,1-methyl-2,6-cyclohexyl diamine, 1,3-diaminopropane, dimethylaminopropylamine, diethylamino propylamine, imido-bis-propylamine, isomersand mixtures of isomers of diaminocyclohexane, monoethanolamine,diethanolamine, triethanolamine, monoisopropanolamine, anddiisopropanolamine. The most preferred saturated curatives are1,4-butanediol, 1,4-cyclohexyldimethylol and4,4′-bis-(sec-butylamino)-dicyclohexylmethane.

Suitable catalysts include, but are not limited to bismuth catalyst,oleic acid, triethylenediamine (DABCO®-33LV), di-butyltin dilaurate(DABCO®-T12) and acetic acid. The most preferred catalyst is di-butyltindilaurate (DABCO®-T12). DABCO® materials are manufactured by AirProducts and Chemicals, Inc.

As used herein, the term “about,” used in connection with one or morenumbers or numerical ranges, should be understood to refer to all suchnumbers, including all numbers in a range.

The invention described and claimed herein is not to be limited in scopeby the specific embodiments herein disclosed, since these embodimentsare intended al illustrations of several aspects of the invention. Anyequivalent embodiments are intended to be within the scope of thisinvention. Indeed, various modifications of the invention in addition tothose shown and described herein will become apparent to those skilledin the art from the foregoing description. Such modifications are alsointended to fall within the scope of the appended claims.

1. A golf ball comprising: (a) a core of at least a first and secondlayer having an outer diameter of at least about 1.55 inches, the firstlayer comprised of an inner core layer and the second layer comprised ofan outer core layer, the inner core layer comprised of a polybutadienerubber and organosulfer compound; (b) a cover layer having a flexmodulus of less than about 20,000 psi; and (c) a mantle layer disposedbetween the core and the cover; wherein the mantle layer comprises anon-ionomeric, thermoplastic material, having a hardness of less than 60Shore D and a resilience of greater than
 34. 2. The golf ball of claim1, wherein the mantle layer has a thickness from about 0.025 inches toabout 0.125 inches.
 3. The golf ball of claim 1, wherein the mantle hasa flex modulus of greater than about 45,000 psi.
 4. The golf ball ofclaim 1, wherein the overall diameter of the finished ball is about 1.68inches to about 1.80 inches.
 5. A golf ball comprising: a core of one ormore layers having a compression of about 30 to 90; a cover of one ormole layers; and a mantle layer disposed between the core layer and thecover formed from a non-ionomeric, thermoplastic elastomer and having avicat point of greater than about 350°F. and a flexural modulus of atleast about 45,000 psi.
 6. The golf ball of claim 5, wherein the coveris comprised of a polyurethane or polyurea based material.
 7. The golfball of claim 5, wherein the core is comprised of an inner core layerand an outer core layer.
 8. The golf ball of claim 5, wherein the mantlehas a Shore D hardness of at least about
 60. 9. The golf ball of claim5, wherein the mantle layer has a thickness of less than about 0.1 inch.10. The golf ball of claim 5, wherein the core has a diameter of atleast about 1.55 inches.
 11. The golf ball of claim 9, wherein the coverlayer has a flex modulus of less than about 20,000 psi.
 12. The golfball of claim 5, wherein the cover is comprised of an inner cover layerhaving a thickness of about 0.005 and 0.06 inches and an outer coverlayer having a thickness of about 0.005 and 0.035.
 13. The golf ball ofclaim 5, wherein the ball has a coefficient of restitution greater thanabout 0.805.